The SM's income being taken into account has been a hot potato on ST. In this country (i'm in europe) it is taken into account but in an indirect way. They don't ask how much an SM is earning and calculate but they do assume that the father's cost of living is now less because he is sharing the bills of rent/mortgage/electricity etc with another, THUS he has more money available.

Personally, we are in the opposite position as my DH had custody. SD is aged out and SS is still here so BM now has to pay us. The amount has not changed in 10 years ago since it was agreed by DH and the Narc. He was stupid and let her off easy with a paltry amount of cs. She never paid ANY extras and if asked to chip in she was abusive and totally refused saying that she was paying cs. The law does say that the cs amount is supposed to be indexed with inflation (goes up a percentage each year) but she has not done that. She is still paying the paltry amount. We cannot risk taking her to court over this stupid amount for the extra but it makes me sick that she gets away with it. If this were any other country I think my DH could get the cs recalculated as she now has a husband working and works more hours. Thus her expenses are less and she is earning more but DH resolutely refuses to go to court.

She only pays equivalent of $61 dollars a month for an 18 year old. Here we are having to pay for adult clothes, shoes, food and all the school fees, extras etc. She never sends a birthday or xmas present. He costs her very little and she wonders why he does not want to see her.

If I had my time again I would not marry a man with children. Maybe one where the kids are grown up etc even though that can also be problematic but at least there's no CS. I thought things would be easier with him being custodial but they haven't. I didn't know just how she had set it all up and twisted his arm and he had played along thinking that it would make things all nice and friendly *fool*. Why do men do this? grrrr

* I just found a cs calculator online, I know what DH earns and have a good idea what the narc earns (all salaries are on an index here and I knew what she earned before and she is now earning more) I put all this into the calculator and it says she should be paying over $500 per month. She is paying $61. He will never go to court though. BM has been so toxic that he doesn't want the trouble or the lawyer's fees. It's irritating though.

I did not read the comments on the link, just the original post with submitted reader's complaint and question.

I found myself with a few questions from the OP (not meaning here, but on the link). 

"The custodial parent, ex-wife, gets 60% of his net income for two children." 

Which state orders 60% of bring home pay for two children . I fail to believe that is an accurate nor entirety of the situation.

"Every time there’s a change in circumstance, (oldest takes piano lessons, youngest enrolls in ballet), we go back to court, pay more legal fees and ultimately, the CS order is increased."

Perhaps there is a state out there somewhere who considers piano lessons and ballet a "change in circumstances" , but I'm hesitant to take that at face value without also a giant grain (entire salt shaker) of salt. I am not saying that there may not be some type of agreement to split of extra curricular activities for the NCP, but extra curricular activities are not considered changes in circumstances in any legal definition of 'changed circumstances' in any state I'm familar with. Anybody? 

"He and his ex-wife both bring home about $3000 per month. Only, we’re only able to see about $1000+/- of his money after withholdings and CS."

It was already said the "bring home pay" (aka 'net pay' , the amount left after deductions such as federal and state taxes and social security withholdings) was about $3000 a piece for both BM and Dad. Yet this appears to be counting withholdings a second time. Unless the peron is having perhaps something else garnished out of his wages. I suppose it could also mean something like the man's health insurance premium and retirement contribution, but health insurance is usually somewhere credited in CS calculations in most states. And retirement contributions, if any, are not  the two minor children's concern when it comes to ability to pay CS. 

And let's face, it, $36,000 a year gross income when one has a wife and two children isn't anything to write home and brag about. Considering the gentleman being long distance parent with CS obligations , this guy wouldn't have a whole lot to his name even leaving CS out of it. And I will note, my comment is not meant to be nasty. She also mentions student loans and depending on cost of living in whatever area they live, that $36,000 a year could mean different things to different people. 

However, after saying all that, I do agree with the OP here (our member being the OP now) that of course her own earnings would supplement any husband who has CS obligations. Because he has less in his own pocket to cover his proper share of household expenses.  No, a stepparent's income, is not usually (extreme and rare instances when are) part of the CS calculations, but to think perhaps a wife/SO isn't putting out more in other expenses (rent, groceries, utilities and the like) would be an inaccurate thought. Unless the husband is making more than the linked article guy, doesn't have previous obligations (such as divorce debt and student loans to mention a couple items).

When the guy has (per the linked article) a whopping $1,000 a month to hopefully contribute to the household? If the man were lucky, without the new wife to assist in household bills and day to day living, he might have enough to rent a efficiency apartment (if he can find one) and groceries for himself plus bus fare. 

It's not hard for CS to consume 50-60 percent of a CS payers take home pay. And sure, we get "reimbursed" for the medical coverage: a whopping $50 credit on monthly CS payments. Our premium: $1,100.

We have plenty of examples of BM's constantly dragging the NCP back to court for more money. "Change of circumstance" is a guideline, not a hardline, and judges can and do exercise their own discretion ALL the time as to what that means.

Low wages, high costs of health care, student loans: these issues put a lot of financial strain on most young families just starting out. Add a divorce and child support, and it makes the struggle even harder.

dup.