Both me and my wife are residing in USA on work visa. we are salaried and file joint taxes every year. If my spouse transfers funds from her bank account to mine, is that considered income in any way and Is there any tax implication on her or on me due to this
No, there are no tax implications for spouses transferring money.
However, do be aware that US banks are required to report transactions over $10,000 to the IRS. This is mainly a defense against money laundering, and it is very unlikely that anyone will look into transfers that you make for legitimate purposes. But, if you structure your transfers so that you make many small transfers instead of one large transfer, for the purpose of avoiding the reporting limit, that can sometimes constitute a separate financial crime called "Structuring." So just do your business normally and don't try to get clever.
Thankyou for your response. In a day, the online banking facility caps the amount of transfer at 10K. So If she had to transfer 40K, lets say, she would need to repeat the transaction of 10K daily for 4 days. She would for sure not want to do it in small chunks, like, 2K per day for 40 days. I think what you mean is that she could use other methods like issuing instructions to bank for transferring the money in 1 go, or issue a check?
If the banking facility caps transfers, that should be a defense against a claim of structuring. However, federal authorities do not always have “common sense” in their vocabulary. There are many cases where “civil forfeiture” has allegedly been abused by government authorities.
I’m not an attorney and can’t give legal advice. For large sums, a wire transfer might be safer for multiple reasons, depending on the financial institutions involved. You may want professional help if you are concerned.