Štelmahers was a member of the Latvia national basketball team from 1992 to 2005 participating in four EuroBasket final tournaments in 1997,[1] 2001,[2] 2003[3] and 2005.

He was released on late December due to club's financial problems and in January moved to Poland, signed by Zielona Góra.

In 2004 he moved back to Baltics and signed with Lithuanian powerhouse Lietuvos Rytas where he stayed until the 2007–08 championship.

[6] The same month, on 30 July, Nymburk announced Stelmahers as their new coach, a move criticised by Leiden's management.

[8] On 29 June 2023, Štelmahers signed a two-year (1+1) deal with Lietkabelis Panevėžys of the Lithuanian Basketball League (LKL) and the EuroCup.