I'm posting this for people that are contemplating between public schools and private schools (hagwons, etc). I am a gyopo F4 visa (Korean-American) my Korean is native level, read, write, speak, etcetc. The only reason why I am stating my Korean fluency level is that it allowed me to reap all the benefits that a non Korean speaker would not have been able to do on their own. First, we have to understand the difference between Public vs Private. The difference between the two types of schools is accreditation. For you to get extra optional perks, you would have to be working in a public/private school accredited by the Korean government or Korean education office. The word you want to look for, next to your school is 인가 or ask your school "does our school have 인가. (https://www.sfis.kr:6548/school/index.php) This link shows all the different types of "international schools" in Korea. Click on a school, scroll down to school type and 인가 means yes accredited and 미인가 means not accredited by the office of education. I am talking about accreditation by Korean government and not foreign governments. (if your schools is accredited by WASC or other stuff that's great, but it is not Korean government accreditation) In order to get other benefits, your school needs to be backed by the Korean government. (if that makes sense) *If your school is 인가 it means the students that graduate will receive a Korean High School Diploma and then take the college entrance exam. 미인가 means students that graduate has to take a test equivalent to a GED test and then take the college entrance exams. Not really much of a big deal, for students. (If you plan on staying in Korea long term, retire, get pension, etc Keep reading, otherwise turn back as it will not benefit you)

How do I tell if my school is 인가 or 미인가?
Schools that are most likely 인가 schools are EPIK schools. Meaning if you work for EPIK you are in a 인가 school. *inga Pronunciation in English
대한학교 or alternative schools. These are private alternative schools aka nearly most of them are "Christian" International curriculum schools. (Read below for 미인가)
I have never worked at a uni, but some uni job posts, I have seen "enroll in Korean Union Plan" or something like that. (one of the perks I will be talking about) If that is the case, then those uni's should be considered 인가 schools.
외국인학교 Foreign school - Most of these schools are the big International schools such as, Seoul International School, Yongsan International School, Taejeon Christian International School, etc. They are registered under the Korean Education Office, but I am not sure if they are considered 인가 maybe someone can find out.
Hagwons, gongbubang's, private academies are not 인가.
"International schools" nearly 90% of the international schools are not 인가. Places that say they are "international schools for kindys" they are just a hagwon for kindys or Christian International School are Christian Hagwons that run foreign curriculum. (beware of international school phrases, just ask them are you 인가)

What benefits do you get from 인가 schools?
Everyone that is employed will have the national pension, health insurance, aka 국민연금. (It is taken automatically out of your paycheck) If your school is not doing this, this is a red flag and leave immediately, unless you are doing it on purpose for whatever reason. Korean teachers are enrolled in a different pension plan, which is the Korean Teachers Pension Plan 사학연금. If you are in enrolled in a 인가 school you yourself as a foreigner can also sign up for the 사학연금 or Korean Teachers Pension Plan. *There's a catch, You need to attend a Korean Education university most likely Graduate school and graduate to receive the Korean Teachers Certificate to enroll for 사학연금. Your Korean needs to be at least fluent as everything is in Korean. It is possible, look at me, with the help of my wife and co teachers you too can do it. What is so great about Korean Teachers Pension plan... only one real thing, which is your pension after you retire your pension is doubled than that of 국민연금. You pay double while employed. For example, instead of paying 150,000 won per month you pay 300,000 won per month into your pension and the employer pays the other half. After 65 years of age, under the national pension plan, after paying 30 years into the national pension plan you get about 1,000,000 won per month for the rest of your life. Under the Korean Teachers Pension plan you would get double that for the rest of your life. (advantages or disadvantages up to you) (https://www.tp.or.kr/tp-kr/index.do) is the site for people interested.
The next things you can enroll in is 교직원공제회 or Korea Teacher's Credit Union (banking and financial plans for Korean Teachers). Here you can apply for loans as a foreigner without cosigners or with Korean spouse visas. I was able to get an apartment loan and then get another loan using this service for other business ventures and all other tax breaks that come with that. Interest rates are super low compared to regular bank loans. For example, I got a fixed rate loan from the Korean Teachers Credit Union for 2.98% fixed rate for 10 years on 50 million won without any headache paperwork on top of my apartment loan which was specifically for buying my apartment which was 2.48% fixed rate for 30 years on 140 million won. Remember no cosigner or Korea spouse needed for both my loans. What else? You are automatically enrolled in the savings account, which you can pay up to 900,000 won per month and if you do for 30 years, your savings account will have 324 million won and the incurred interest will have you taking out almost double of up to 600 million won after your 30 years. Other services include, discounted prices at hotels, lotteworld tickets, or first child stipends, marriage stipends, gifts, etc. (https://www.ktcu.or.kr/LN/LN-P010T01.do) check here for website.

My opinion...
If you plan to stay in Korea long term, (married with kids, whatever) and do not plan on going back home, 인가 schools will help you out in the long run because of the pension plan and savings account plan. It helps you to get easy loans, credit cards, and other perks that may or may not help you buy a home set up a hagwon etc. Many foreigners probably do not know about these types of benefits and if you are worried about your future in Korea then these options may or may not help you. Obviously if you stay long term, your visa will probably be an F visa and everything that I am doing, you can do also.

If you plan on leaving and staying short term, then chase the money and grab as much money you can from anybody and leave. Retirements savings, pensions and other things should not concern you. If you are also super rich and were able to flat out buy everything by having a great business and whatever then again your own pension plans and savings account and other investments should be way better than that of the things I have listed. To those who have read the whole things congrats. Hope this post can help future expats in their decisions.

What benefits do you get from 인가 schools?
Everyone that is employed will have the national pension, health insurance, aka 국민연금. (It is taken automatically out of your paycheck) If your school is not doing this, this is a red flag and leave immediately, unless you are doing it on purpose for whatever reason. Korean teachers are enrolled in a different pension plan, which is the Korean Teachers Pension Plan 사학연금. If you are in enrolled in a 인가 school you yourself as a foreigner can also sign up for the 사학연금 or Korean Teachers Pension Plan. *There's a catch, You need to attend a Korean Education university most likely Graduate school and graduate to receive the Korean Teachers Certificate to enroll for 사학연금. Your Korean needs to be at least fluent as everything is in Korean. It is possible, look at me, with the help of my wife and co teachers you too can do it. What is so great about Korean Teachers Pension plan... only one real thing, which is your pension after you retire your pension is doubled than that of 국민연금. You pay double while employed. For example, instead of paying 150,000 won per month you pay 300,000 won per month into your pension and the employer pays the other half. After 65 years of age, under the national pension plan, after paying 30 years into the national pension plan you get about 1,000,000 won per month for the rest of your life. Under the Korean Teachers Pension plan you would get double that for the rest of your life. (advantages or disadvantages up to you) (https://www.tp.or.kr/tp-kr/index.do) is the site for people interested.
The next things you can enroll in is 교직원공제회 or Korea Teacher's Credit Union (banking and financial plans for Korean Teachers). Here you can apply for loans as a foreigner without cosigners or with Korean spouse visas. I was able to get an apartment loan and then get another loan using this service for other business ventures and all other tax breaks that come with that. Interest rates are super low compared to regular bank loans. For example, I got a fixed rate loan from the Korean Teachers Credit Union for 2.98% fixed rate for 10 years on 50 million won without any headache paperwork on top of my apartment loan which was specifically for buying my apartment which was 2.48% fixed rate for 30 years on 140 million won. Remember no cosigner or Korea spouse needed for both my loans. What else? You are automatically enrolled in the savings account, which you can pay up to 900,000 won per month and if you do for 30 years, your savings account will have 324 million won and the incurred interest will have you taking out almost double of up to 600 million won after your 30 years. Other services include, discounted prices at hotels, lotteworld tickets, or first child stipends, marriage stipends, gifts, etc. (https://www.ktcu.or.kr/LN/LN-P010T01.do) check here for website.

So, I have never heard of a foreigner going to Korean teachers university and being hired as a Korean like teacher.  So, what was the point of writing this?  Foreigners will not qualify for any of this.  But it definitely does show unequal treatment between the foreign teachers and the Korean teachers.  As I mentioned before recently a teacher who taught for 23 years said with bonuses and other perks added onto his salary that he would make around 6 million won a month.  A foreign teacher will make whatever level 1 plus is in your area.  So, hardly an incentive.  The schools all say they want experienced teachers but they sure don't pay like they do nor incentivize it. 

 . This is awesome information. I wasn't sure I could do a teaching license program here! Now that I know, I can set myself up better.

Thank you for sharing.

The point is most foreigners are still treated unequally in the schools here.  Korean teachers get pay raises and foreigners do not even if they have a teaching degree from back home.  Most are not going to go to Korean teachers university when they already went to a university.  Either way the guest of honor treatment we use to get years ago has gone the way of the dodo bird and has been replaced with stubborn inflexibility with no negotiation allowed, even in the rural areas lately.  No pay raise for years.  Shit and disrespect all the way around.

Hi Hangook! I think OP just wanted to share that it's possible for a foreigner to do this. Of course not all foreigners will go to Korean Uni and get teaching license, but it was great information for OP to tell us this can be an option. OP, thank you for sharing, we all appreciate it and I'm sure some other foreigners might consider doing this if they stay in Korea long term.

Exactly Texas Mel. Not a lot of joy and positivity in some people.

Plenty of joy and positivity but just a fact that going to Korean teachers school is not an option for most people.  Still not an excuse for keeping foreign teachers pay low.  But if you want to shill for the status quo, fill your boots. 

The status quo for me is great! I work 18 hours a week and I'd bet that I earn a bit more than you, so stop dragging everyone into your dark, narrow corner. Some of us have actually worked hard and upgraded our skills instead of bitchin about everyone and everything. You are nothing more than a hot air balloon (and a broken record).

Also, this thread isn't about you responding to an informative post with your usual negativity. You plain got it wrong with your initial comments. You don't need to jump on every thread and bring up wages, China, the good old days, or how Korea sucks. This thread is about pointing out options, realistic or not. Your career being so stagnant...what with hitting middle age and all, you could do with more advice like the OPs, and Billy's. Jesus, just think for once, instead of blurting out the usual! It's boring!

So are you actually being paid for upgrading those skills?  You making 4 or 5 million won a month now?  If so, then yes, I can see why you would stay and be happy.